Extended Comparison Rule 2:If a decision cannot be reached by ranking the 1st atoms in the substitutent,look at the 2nd,3rd or 4th atoms away from the double-bond carbons until the first difference is found H HH H 之C-H 之C-C-H 之0一H 之0-C-H H HH Lower H Lower Higher Higher CH3 H CH3 H 之0- CH3 CH 之C-NH2 之C-C H H H H Higher Lower Lower Higher 04mRule 2: If a decision cannot be reached by ranking the 1st atoms in the substitutent, look at the 2nd, 3rd or 4th atoms away from the double-bond carbons until the first difference is found Extended Comparison